// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_COMPOSITOR_LAYER_ANIMATOR_COLLECTION_H_
#define UI_COMPOSITOR_LAYER_ANIMATOR_COLLECTION_H_

#include <set>

#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/time/time.h"
#include "ui/compositor/compositor_animation_observer.h"
#include "ui/compositor/compositor_export.h"

namespace ui {

class Compositor;
class LayerAnimator;

// A collection of LayerAnimators that should be updated at each animation step
// in the compositor.
class COMPOSITOR_EXPORT LayerAnimatorCollection
    : public CompositorAnimationObserver {
public:
    explicit LayerAnimatorCollection(Compositor* compositor);
    ~LayerAnimatorCollection() override;

    void StartAnimator(scoped_refptr<LayerAnimator> animator);
    void StopAnimator(scoped_refptr<LayerAnimator> animator);

    bool HasActiveAnimators() const;

    base::TimeTicks last_tick_time() const { return last_tick_time_; }

    // CompositorAnimationObserver:
    void OnAnimationStep(base::TimeTicks timestamp) override;
    void OnCompositingShuttingDown(Compositor* compositor) override;

private:
    Compositor* compositor_;
    base::TimeTicks last_tick_time_;
    std::set<scoped_refptr<LayerAnimator>> animators_;

    DISALLOW_COPY_AND_ASSIGN(LayerAnimatorCollection);
};

} // namespace ui

#endif // UI_COMPOSITOR_LAYER_ANIMATOR_COLLECTION_H_
